JP2009519779A - System and method for analyzing cardiovascular pressure measurements made in the human body - Google Patents

Abstract

One or more embedded pressure sensors 104, an embedded communication device 102 in wireless communication with the one or more sensors, and to use real-time barometric pressure data to calibrate uncalibrated pressure data received from the communication device 102 A cardiovascular pressure data analysis system 110 having an external processing unit 106 configured. The external processing unit 106 may be portable and may communicate with the remote database 108 to transfer calibrated pressure data to the remote database and / or provide reprogramming information to the communication device. is there.

Description

  The present invention relates to a medical device that is implanted in the human body to measure blood pressure and other physiological parameters. More specifically, the present invention relates to wireless communication of physiological parameter data to an external processing device.

  Medical devices are known that are implanted in a patient's body to monitor one or more physiological parameters and / or to perform a therapeutic function. For example, sensors or transducers can be placed in the body to monitor various properties such as temperature, blood pressure, strain, flow rate, posture, respiration, chemical properties, electrical properties, magnetic properties, and the like. In addition, medical devices that perform one or more therapeutic functions such as cardiac pacing, defibrillation, electrical stimulation, and the like may be implanted.

  In many cases, the implantable medical device is, for example, with an external controller or programmer to communicate data between the implantable medical device and an external programmer and / or to activate or control the implantable medical device. Set or configured to communicate. In general, an implantable medical device communicates with an external programmer via a wireless communication link, such as a radio frequency (RF) communication link, or other acceptable technology.

  As described above, implantable medical devices are configured to measure or sense a number of different parameters within the body. One particularly important parameter is blood pressure. However, implantable biosensors that measure pressure deep within an anatomical structure generally can only communicate absolute pressures associated with the immediate anatomical environment. Since these devices are confined and sealed away from ambient pressure outside the body, they cannot communicate gauge pressure.

  One way to convert absolute pressure to gauge pressure is to compare absolute measurements made by an implantable medical device with measurements of atmospheric pressure made outside the body in an external device such as a programmer. US Patent Application No. 10/934626 "SYSTEMS AND METHODS FOR DERIVING RELATIVE PHYSIOLOGIC MEASUREMENT 69 USENG TECH NITEG TEN GIN TEN MING TEN GIN TEN GIN TEN GIN TEN GIN TECHN No. "SYSTEM AND METHOD FOR DERIVING RELATIVE PHYSIOLOGIC MEASUREMENTS USING AN EXTERNAL COMPUTING DEVICE", US Patent Application No. 10/942711 "S "STEMS AND METHODS FOR DERIVING RELATIVE PHYSIOLOGIC MEASUREMENTS USING AN IMPLANTED SENSOR DEVICE" each discloses a method and apparatus for converting absolute pressure readings of implantable medical devices to gauge readings by external devices. Is incorporated herein by reference.

  However, individual implantable medical devices may have different linearities, gains, offset factors from ideal values, and they may also vary from sensor to sensor, thereby causing errors in pressure data, For example, a sensor of the type that is embedded to read blood pressure in the human body may provide raw data that reads a change from the actual absolute pressure. In order to compensate for these potential errors, the sensor needs to be calibrated. It is known to calibrate sensor information in implantable medical devices. Using an implantable medical device for calibration purposes is another challenge, especially necessary to provide adequate computing power within the implantable medical device to achieve the desired accuracy and accuracy and to perform such calculations over time. It is a difficult problem to give additional power.

  Therefore, calibrate measured physiological parameters such as pressure, temperature, etc. based on ambient or other environmental conditions and inherent errors introduced by individual sensors without increasing the power consumption of the implantable medical device There is a need for a system, method and / or apparatus to do so.

  The present invention is directed to a system for analyzing cardiovascular pressure data in a human body. The system includes a sensor embedded in a human body to measure pressure data, an embedded communication device capable of wirelessly communicating with the sensor to receive pressure data from the sensor in an uncalibrated shape, and wireless communication from the communication device An external processing device that receives uncalibrated pressure data and calibrates the pressure data. The external processing device includes a barometric sensor that provides real-time barometric data used by the external processing device to generate relative pressure data.

  The present invention is also directed to a system for analyzing blood pressure data corresponding to blood pressure in the human body, including an embedded sensor means for collecting diagnostic information in the human body. The system further includes communication means for communicating diagnostic information and an external processing device that automatically receives and calibrates the diagnostic information.

  The present invention is further directed to a method for analyzing pressure data in a human body. The method includes using an implantable pressure sensor that collects pressure data from the body. Once pressure is collected by the sensor, it is communicated to the embedded communication device and then to the external processing device, which calibrates the pressure data by compensating for the inherent characteristics of the sensor.

  While multiple embodiments are disclosed, other embodiments of the invention will be apparent to those skilled in the art from the following detailed description, which illustrates and describes exemplary embodiments of the invention. . Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

  FIG. 1 illustrates measuring physiological parameters within a human patient, transferring measurement data outside the human patient with or without human intervention, and human patient according to one exemplary embodiment of the present invention. 1 shows a system using an implantable medical device that calibrates external measurement data.

  FIG. 2 is a block diagram of a communication device implanted in a human patient as part of the system shown in FIG.

  FIG. 3 is a block diagram of a physiological sensor implanted in a human patient and configured to communicate with the communication device of FIG.

  FIG. 4 is a block diagram of an external processing device configured to communicate with one or more implantable medical devices by the human patient of FIG.

  FIG. 5 is a functional block diagram of a process for measuring and storing physiological data within the human patient of FIG.

  FIG. 6 is a functional block diagram of a process for transferring the physiological data measurements shown in FIG. 6 from a human patient for calibration and analysis.

  While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are described in detail below. However, the intention is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

  FIG. 1 illustrates a system 110 for measuring physiological parameter data in a human patient 100 and accurately calibrating the measurement data according to one exemplary embodiment of the present invention. The system 110 includes at least one communication device 102, at least one physiological sensor 104 implanted in the human patient 100, an external processing device 106, and a remote database 108. Communication links 112, 114, 116 provide the ability to transfer information between the various components of system 110.

  The communication device 102 may be any type of implantable medical device capable of wireless communication with the external processing device 106 to communicate sensor data collected within the human patient 100 to the external processing device 106. For example, the communication device 102 may be a pulse generator configured to obtain physiological parameter measurements from a human patient's body and provide treatment to the patient. Examples of pulse generator types including communication device 102 are pacemakers, implantable defibrillators, cardiac resynchronizers, biventricular pacers, ventricular assist blood pumps, drug delivery pumps, drug infusion devices, nerve stimulation devices. . This list is intended to be non-limiting, as other acceptable pulse generators can be used. In one exemplary embodiment, the communication device 102 is a pacemaker or an implantable defibrillator. Alternatively, the communication device 102 may not have a treatment function. For example, the communication device 102 may be a device that is provided exclusively for communication with other devices placed inside and / or outside the human patient 100. Other acceptable communication devices can perform other non-therapeutic functions. As an example, the communication device 102 can measure physiological parameter data.

  The physiological sensor 104 in the illustrated embodiment is a pressure sensor that measures the absolute blood pressure of the human patient 100. The physiological sensor 104 can be placed at various locations within the human patient 100, including any of a number of blood vessels (not shown) within the heart 120 or within the human patient. In addition, the system 110 may include a plurality of physiological sensors 104 to measure other parameters such as body temperature, blood oxygen level or blood glucose level, blood flow, respiration, posture. Alternatively, a single physiological sensor 104 can measure multiple parameters. Alternatively or in addition, one or more physiological sensor elements similar to elements in physiological sensor 104 (described below) can be disposed in communication device 102. Some of these parameters are useful when analyzing blood pressure data. Others are useful in other physiological analyses. While one exemplary embodiment described herein relates to a system for measuring and calibrating blood pressure data that provides an analysis of the human cardiovascular system, alternative embodiments provide data relating to other body functions. Can be measured and calibrated. Moreover, while the exemplary embodiment of the system 110 describes the physiologic sensor 104 remote from the communication device 102, the system in alternative embodiments includes one or more sensor elements integrated therein. Including a communication device 102. Such a system may or may not have a physiological sensor 104 mounted in a package separate from the communication device 102.

  The external processing device 106 is disposed outside the human patient 100. In one exemplary embodiment, the external processing device 106 is a handheld device. Alternatively, the external processing device 106 may be a portable device of any size. Alternatively, the external processing device 106 is a fixed device. In other embodiments, the external processing device 106 is a pager, watch, mobile phone, or personal data assistant configured to perform the functions of the external processing device 106 as required within the system 110. It may be a commercial electronic device such as (PDA).

  The external processing device 106 can communicate with an implantable medical device, such as the communication device 102, to receive physiological data measured within a human patient. In addition, the external processing device 106 performs mathematical calculations to calibrate the received physiological data. Further, the external processing device 106 communicates information to an implantable medical device such as the communication device 102 to initiate data transfer from the communication device 102 to the external processing device 106 and for other purposes that will become apparent. It is possible.

  The remote database 108 in the illustrated embodiment can be located anywhere with respect to other components of the system 110. The remote database 108 includes information communicated from the external processing device 106 via the communication link 116. In addition, the remote database 108 contains information that can be used by the external processing device 106. For example, the remote database may have calibration data for each unique physiological sensor that the external processing device 106 uses in its calibration procedure. In addition, the remote database 108 can include information or code for any software, or calibration corrections or other data that can be used with any implantable medical device. The remote database 108 can store not only all relevant diagnostic information obtained from the human patient 100 but also information from other human patients. The remote database 108 can provide a variety of data analysis, including trend analysis of data collected from human patients 100 over time. The remote database 108 has access to this information for individuals who are appropriate and legally authorized to obtain this information and who need the information to provide medical care to human patients.

  In one exemplary embodiment, communication link 112 is a communication link between the various implantable medical devices of system 110. For example, the communication device 102 communicates with a physiological sensor 104 located outside the communication device 102 via a communication link 112. The nature of the information transferred between the communication device 102 and the physiological sensor 104 is discussed below. The communication link 114 is a communication link that enables communication between one or more of the implantable medical devices and the external processing device 106. For example, the communication device 102 can communicate with the external processing device 106 via the communication link 114 to export information collected in the human patient 100 to the external processing device 106. Communication link 114 also allows external processing device 106 to communicate information to an implantable medical device, such as communication device 102. The nature of the information transferred from the external processing device 106 or the implantable medical device will be discussed in more detail below. Communication link 116 provides a communication path to allow information exchange between external processing device 106 and remote database 108, as discussed below.

  FIG. 2 is a block diagram of a communication device 102 according to one exemplary embodiment showing some of the more related forms of communication device circuitry. The communication device 102 includes a processor 202, a memory 204, a communication circuit 206, and a treatment circuit 208. Memory 204, communication circuit 206, treatment circuit 208 is in electrical communication with processor 202 as represented by circuit connection 210. Alternatively, as described above, the communication device 102 can include one or more sensor circuits (not shown) of the type described below in connection with the physiological sensor 104.

  The processor 202 is any suitable processing device, such as a microcontroller, or any circuit that provides processing power to control communication, memory storage, and therapy functions performed by the communication device 102. There may be. Memory device 204 is an EEPROM or any other suitable memory device. The communication circuit 206 may be a near field and / or far field radio frequency (RF) communication connection, an acoustic communication connection (eg, an ultrasonic connection), Bluetooth, or any other suitable wireless communication connection, such as Includes circuitry necessary for wireless connection. It should be appreciated that these examples are for illustrative purposes only. Any other suitable communication can be used and therefore support circuitry is included in the communication device 102. Alternatively, or additionally, the communication circuit 206 can include a driver for a wired connection between the communication device 102 and the physiological sensor 104.

  In one exemplary embodiment, the communication device 102 provides a gateway between the physiological sensor 104 and the external processing device 106. Data collected by the physiological sensor 104 is communicated to and stored in the communication device 102, which then communicates the data to the external processing device 106 at an appropriate time. Therefore, the communication circuit 206 can include more than one type of communication circuit. For example, the communication circuit 206 comprises an RF circuit for the communication link 114 between the communication device 102 and the external processing device 106 and an acoustic communication connection for the communication link 112 between the communication device and the physiological sensor 104. ing. Alternatively, the system 110 includes a plurality of physiological sensors 104 having a plurality of communication methods, thereby requiring the communication link 112 to include circuitry for the communication methods required for each.

  The therapy circuit 208 includes, for example, suitable circuitry for providing cardiac pacing therapy, cardiac defibrillation therapy, cardiac resynchronization therapy, or any other therapy associated with a suitable communication device 102, A circuit for providing the above therapeutic functions to the patient is included. Alternatively, as described above, the communication device 102 does not include a therapy function and therefore does not include any therapy circuit.

  The physical implementation of the communication device 102 may vary widely. For example, an integrated circuit such as an application specific integrated circuit (ASIC) that includes the functions represented by the processor 202 includes a memory device 204, and further circuits necessary for other functions including a communication circuit 206 and a therapy circuit 208. Including some or all of the above. Further, the communication device 102 can also include other circuits not shown in FIG. 2, such as power saving circuits, random access memory, and various other circuits necessary for the function of the communication device. The descriptions herein are for illustrative purposes only and are not intended to be limiting.

  FIG. 3 is a block diagram of the physiological sensor 104 according to one exemplary embodiment. The physiological sensor 104 includes a processor 220, one or more sensor elements 222, a memory 224, and a communication circuit 226. Sensor element 222, memory 224, and communication circuit 226 are in electrical communication with processor 220 as represented by circuit connection 228. Like processor 202, processor 220 may be any suitable processing device or circuit.

  Sensor element 222 includes a sensing component that is exposed to a given physiological phenomenon, such as blood pressure, and provides an electrical signal that characterizes the relative amount of phenomenon present. The sensor element 222 further includes any circuitry necessary to condition and / or amplify the signal from the sensing component. For example, the sensor element 222 that senses blood pressure includes a pressure sensing component and associated signal conditioning circuitry. The signal conditioning circuit conditions the signal to prevent saturation of the sensing component, amplify the signal provided by the pressure sensing component, and / or convert the analog signal to a digital signal. The conditioned signal of sensor element 222 provides an analog or digital output signal having a range of values corresponding to the pressure range that can be measured by the sensor element. It should be understood that the sensor element 222 provides a conditioned signal, but the signal is not calibrated.

  Memory device 224 includes sufficient memory space for any software, firmware, or other code related to the operation of physiological sensor 104, including any software for performing communication functions. Moreover, the memory element 224 can hold parameters such as calibration data specific to a given physiological sensor and sensor identification information. As described above, sensor element 222 provides an output signal that is a function of pressure. Individual sensor elements 222 have a similar relationship between pressure and their respective output values, but there is some significant variation between the output signals of the individual sensors depending on the pressure. To compensate for variations, calibration data is used to describe the relationship of each sensor with appropriate accuracy. The calibration data can include factors relating to, for example, linearity, gain, and offset. Such data is loaded into memory during the manufacturing inspection process.

  In one exemplary embodiment, the physiological sensor 104 can be reprogrammed after implantation in the human patient 100. Reprogramming can include reprogramming operation code, calibration data, or other software, firmware, or code in the sensor. Therefore, at least some of the memory elements 224 require a reprogrammable memory, such as an electrically erasable programmable read only memory (EEPROM), a reprogrammable flash memory, or other acceptable reprogrammable memory.

  In one exemplary embodiment, the communication circuit 226 includes the circuitry necessary for wireless communication with other implantable medical devices such as the communication device 102 or other physiological sensors 104 on the communication link 112. . Alternatively, the communication circuit 226 can also include a circuit for communicating with the remote processing device 106. For example, in order to provide the ability of the physiological sensor 104 to communicate via the communication link 112 and / or the communication link 114, the communication circuit 226 includes a near field and / or far field radio frequency (RF) communication link, Circuitry for acoustic (eg, ultrasound) communication links, Bluetooth, or any other suitable wireless link connection or link combination may also be included. Alternatively, the communication circuit 226 can include a driver for a wired connection between the physiological sensor 104 and the communication device 102.

  The physical implementation of the physiological sensor 104 may vary widely and is represented by the processor 220 and the memory device 224 and further by the circuitry required for other functions including the communication circuit 226 and the sensor element 222. Including, but not limited to, an integrated circuit such as an ASIC that performs some or all of the functions. In addition, the physiological sensor 104 may include other circuits not shown in FIG. 3, such as power saving circuits, random access memory, and various other circuits necessary for the function of the physiological sensor.

  FIG. 4 is a block diagram of an external processing device 106 according to one exemplary embodiment. The external processing device 106 includes a processor 230, a sensor element 232 that senses ambient air pressure, a memory 234, a communication circuit 236, and a user interface 238. Sensor element 232, memory 234, and communication circuit 236 are in electrical communication with processor 230 as represented by circuit connection 235.

  The processor 230 may be any suitable processing device or circuit for performing the functions required by the external processing device 106. The communication circuit 236 includes the circuitry necessary to support wireless communication with the implantable medical device such as the communication device 102 or the physiological sensor 104 via the communication link 114. The communication link 114 may utilize one of the following communication technologies and may require the necessary circuitry. Near field and / or far field radio frequency (RF), or acoustic communication (eg, ultrasound) technology. These examples are for illustrative purposes only. Any other suitable communication can be used, and in such a case, support circuitry is included in the external processing device 106.

  The sensor element 232 includes a sensing component that senses atmospheric pressure and any circuitry necessary to condition and / or amplify the signal from the sensing component. The sensor element 232 is disposed within the external processing device 106 in one exemplary embodiment. Sensor element 232 is electrically coupled to processor 230 via circuit connection 235 to read atmospheric pressure in real time. Alternatively, the external processing device 106 may not have the integrated sensor element 232, but rather may be able to communicate with an external atmospheric pressure sensor (not shown) so as to receive a real-time atmospheric pressure reading.

  Memory 234 includes EEPROM, flash memory, hard disk drive, or any other suitable memory device having sufficient memory space for any software, firmware or other code related to the operation of external processing device 106. In addition, the memory device 224 can hold parameters such as calibration data and sensor identification information specific to a particular physiological sensor. In addition, the memory 234 is large enough to store information communicated from the implantable medical device and, if necessary, information such as reprogramming data for the implantable medical device.

  External processing device 106 may also include a user interface 238 in one embodiment. The user interface 238 includes a display screen that displays information to a human patient, medical personnel, and the like. Moreover, the external processing device 106 may include a keyboard, keypad, input switch, or other suitable device for entering information into the external processing device 106.

  The external processing device 106 can communicate with the remote database 108 over the communication link 116 to exchange information between the external processing device 106 and the remote database 108. The communication link 116 between the external processing unit 106 and the remote database 108 may be a modem, a link using the Internet, a near field and / or far field RF communication connection, Bluetooth, or any other similar data communication. The format can be used to include a direct telecommunications link between the external processing device 106 and the remote database 108. The nature of the information exchanged between the external processing device 106 and the remote database 108 is discussed below.

  FIG. 5 shows a functional flow diagram of a sensor data collection event 300, according to one representative embodiment. Data collection event 300 includes collecting sensor data by physiological sensor 104 and storing the information in human patient 100. The following process relates to a single physiological sensor 104 that reads a single parameter, but as noted above, it will be appreciated that some human patients have multiple physiological sensors. Furthermore, one or more physiological sensors 104 in the human patient 100 can measure more than one parameter. In such cases, sensor data collection event 300 may be performed to collect data from each of a plurality of parameters, including several cases where a single sensor provides data to multiple sensors. Further, it should be appreciated that when the human patient 100 has multiple implanted physiological sensors 104, each of the multiple physiological sensors can collect data simultaneously.

  Step 302 initiates a physiological sensor data collection event 300. In one embodiment, the physiological sensor 104 functions in a reduced function or “sleep” mode when not actively reading sensor data. Sleep mode allows the physiologic sensor 104 to reduce the power consumption of its circuit and thus improve battery life. Periodically, the communication device 102 wakes the physiologic sensor from sleep mode and initiates communication with the physiologic sensor 104 via the communication link 114 to read the sensor. Alternatively, or in addition, and as described above, the communication device 102 can include a sensor device. Therefore, the communication device 102 can periodically initiate its own data collection with communication via the communication link 114 with any physiological sensor 104 that can be implanted in the human patient 100.

  The frequency of the periodic data collection event is preset in the communication device 102 or programmed in advance. For example, the communication device 102 can be programmed to start the sensor data collection event 300 four, six, or eight times per day, although the frequency can be changed without departing from the scope of the present invention. Furthermore, the frequency can be changed by reprogramming the communication device 102 after it has been implanted in a human patient. Alternatively or additionally, the communication device 102 can initiate a sensor data collection event 300 in response to a communication request received from an external source. For example, the external processing device 106 initiates a request to the communication device 102 to initiate a sensor data collection event 300. In yet another embodiment, the external processing device 106 initiates a sensor data collection event 300 directly by the physiological sensor 104. For example, the human patient 100 or health care provider can operate the external processing device 106 to initiate a data collection signal. In yet another embodiment, the physiological sensor 104 periodically initiates a sensor data collection event 300 in response to a periodic signal generated within the physiological sensor itself.

  When the physiological sensor 104 receives a communication from another device, such as the communication device 102, to initiate a sensor data collection event 300, the physiological sensor is suitable for receiving sensor data. Confirm that a signal has been received from the device initialized to For example, the communication device 102 can include a unique sensor identification in the original transmission to the physiological sensor 104 to provide confirmation. Alternatively, the physiological sensor 104 can request sensor identification information from the communication device 102, at which point the communication device 102 provides sensor identification information. In one exemplary embodiment, the sensor identification information is encrypted for data security. If the physiological sensor 104 does not determine that the request for sensor data it has received is intended to prompt the physiological sensor to perform the data collection event 300, the physiological sensor will detect the sensor data collection event. Do not execute. Alternatively or additionally, the physiological sensor 104 responds to a request from a device such as the communication device 102 without requiring confirmation.

  As mentioned above, it should be appreciated that a single human patient may have multiple physiological sensors 104 placed within the human body. A single communication device 102 can send communications to multiple physiological sensors 104 to initiate a sensor data collection event 300. Alternatively, the human patient may also have multiple implanted communication devices 102 that can initiate a sensor data collection event 300 by one or more physiological sensors 104.

  Once the physiological sensor 104 determines that the data collection request is appropriate, or “wakes up” from sleep mode, the physiological sensor performs step 304 of measuring a physiological parameter. In one exemplary embodiment, the physiological sensor 104 takes one or more readings of associated physiological parameters over a given period of time, for example, 10-15 seconds. Alternatively, the physiological sensor 104 can measure physiological data for any length of time and can take any number of readings over that length of time. Once uncalibrated physiological data is collected by sensor element 222, it is stored in memory 224. Physiological sensor 104 is measured by the sensor over a single data point measured by sensor element 222, an average of several data points taken over a given time interval, and / or over a given amount of time. Multiple data points can be stored.

  When the physiological parameter is measured, step 306 is performed to transfer the uncalibrated physiological data. In one exemplary embodiment, physiological data is transferred from the physiological sensor 104 to the communication device 102 and stored in the memory 204. The transferred data is given a time stamp in the memory 204 to correlate the data with the time at which it was actually measured. Alternatively, the transferred data has a time stamp provided when the data is collected in the physiological sensor 104. Alternatively or additionally, the time stamp is not provided by the physiological sensor 104 or the communication device 102.

  In one exemplary embodiment, physiological data is communicated between physiological sensor 104 and communication device 102 via communication link 112, and the data is then stored in memory 204 of the communication device. The Once the data collection event 300 is complete, the physiological sensor 104 returns to sleep mode. Alternatively or additionally, communication device 102 includes a sensor and physiological data is transferred internally within the communication device and stored in memory 204.

  FIG. 6 shows a functional flow diagram of the analysis 320 of the process of collecting, transferring, and analyzing physiological data according to one representative embodiment. Step 322 is a step of initiating data transfer of physiological data collected from the implantable medical device in the human patient 100 to the external processing device 106. In one exemplary embodiment, step 322 includes a data transfer request in the form of a communication sent over a communication link 114 with an implantable medical device, such as external processing device 106 or communication device 102. . In one exemplary embodiment, the communication device 102 is designated to initiate the data transfer request of step 322 by sending a data transfer request to the external processing device 106. Alternatively, the external processing device 106 can be designated as such. The automated data transfer request can be sent periodically, such as once per hour, once per day, once per week, or once in any other periodic time frame. Alternatively or in addition, the external processing device 106 can be operated at any time to request data transfer.

  Once the data transfer request communication is transmitted, for example, by the communication device 102, the communication device waits for a response from the external processing device 106 to establish communication. The external processing device 106 does not respond, for example, if the human patient 100 is outside the communication range of the external processing device 106. If the external processing device 106 does not communicate with the communication device 102, a subsequent attempt is made immediately after the failed attempt or at the next specified time. If communication device 102 is designated as the device that initiates step 322 and external processing device 106 has not received a physiological data transfer request in a given period, external processing device 106 initiates data transfer. In order to do so, it periodically tries to establish communication with the communication device. If the external processing device 106 is designated as the device that initiates step 322 and the communication device 102 has not received a request in a given time period, the communication device will also attempt to initiate a transfer periodically. Try to.

  Once communication is established between the external processing device 106 and the communication device 102, the communication device must determine whether the external processing device 106 has permission to receive data from the communication device 102. Information identifying a specific communication device 102 and / or physiological sensor 104 for placement within a human patient is requested by the communication device 102 or provided by an external processing device 106 as part of the initial message. If the external processing device 106 provides appropriate information, the step 322 of initiating data transfer is successfully completed.

  It should be understood that multiple external processing devices 106 have appropriate sensor identification information or communication device identification information for a given human patient. Thus, multiple external processing devices 106 may be within the range of the human patient and step 322 can be successfully completed at the same time. In one embodiment, each external processing device 106 that successfully completes step 322 can move to a subsequent step 324 that receives information from the communication device 102 at the same time, and the communication device can receive all authorized external devices. It can be effectively transmitted to the processing device 106.

  Alternatively, a plurality of external processing devices 106 may have a given priority state, and the communication device 102 may establish communication with the external processing device 106 with the highest priority. For example, a fixed external processing device placed in a medical center has a higher priority than a handheld external processing device. In such a situation, the communication device communicates only with the external processing device 106 having the highest priority. Various communication protocols can be used to limit communication from the communication device 102 to only the highest priority external processing device 106.

  Step 324 of transferring physiological data from the human patient 100 to the external processing device 106 includes transferring physiological data from the communication device 102 to the external processing device 106. In one embodiment, the communication device 102 provides data previously collected from a sensor, such as the physiological sensor 104, and time stamp information. Alternatively, once step 322 of initiating data transfer is successfully completed, the communication device 102 initiates a data collection event 300. In that case, the step 324 of transferring data does not require transferring time stamp information.

  Moreover, transferring the physiological data step 324 can include transferring calibration data specific to the physiological sensor 104. Alternatively, the calibration data is pre-loaded into the external processing device 106 and therefore that information need not be communicated from the communication device 102 to the external processing device 106. Alternatively or additionally, the communication device 102 can communicate a calibration version identifier to indicate which version of calibration data is stored in the physiological sensor 104. When the calibration version identifier in the physiological sensor 104 matches that of the calibration version identifier in the external processing device 106, there is no need to download calibration data with each transmission. However, if the communication device 102 or the external processing device 106 has a new version of calibration data for the particular physiological sensor 104 in question, the device with the new calibration version will have the other device updated with the latest information. The information is sent to another device so that the memory can be reprogrammed.

  The step 324 of transferring physiological data from the human patient to the external processing device 106 is to collect data stored and stored during a single sensor data collection event 300 from a single physiological sensor 104. Including transferring a data point or a plurality of data points. Alternatively, transferring physiological data step 324 may include transferring data from a plurality of previously performed data collection events 300. It should be appreciated that the step 324 of transferring physiological data can include transferring data from multiple physiological sensors 104 via one or more communication device 102 devices.

  Each transfer requires the external processing device 106 to identify each sensor that is to be the source of the data. All transferred information is stored in the memory 234 of the external processing device 106. In one exemplary embodiment, the external processing device 106 determines that when data is transferred from a human patient, if the transferred data does not include a time stamp, for example, step 300 is performed as described above in step 322. Provide a time stamp on the data if executed in response to successful completion of In addition, the external processing device 106 reads atmospheric pressure from a sensor arranged in the external processing device 106 or receives atmospheric pressure from a sensor arranged outside. Atmospheric pressure information is stored in the memory 234 of the external processing device 106 with a time stamp if previously collected or with collected data if collected at the same time as the data collection event 300.

  A plurality of external processing devices 106 communicate with a single communication device 102 or a plurality of communication devices within a single patient and provide physiological data measured by one or more physiological sensors 104 within the human patient 100. It will be appreciated that a single external processing device 106 can be properly initialized to communicate with a plurality of different communication devices 102 located within a plurality of human patients so that it can be properly initialized for receiving. Should be. Data associated with each human patient collected in the external processing device 106 is stored in the memory 234 to keep data from one human patient distinct from data collected from the other.

  Once the data is transferred from the human patient to the external processing device 106, the external processing device 106 performs step 326 of calibrating the physiological data. Calibrating the physiological data step 326 includes converting the raw data into more accurate blood pressure data, which includes a number of different processes. One step in the calibration process involves calculating the effect of individual sensor errors. Calibration data stored in the human patient (in the physiological sensor 104 and / or the communication device 102) and in the external processing device 106 reveals known variations in the linearity, gain, and offset of a given sensor. Calibrate the data to Another step in the calibration process is to subtract atmospheric pressure from readings made in the human patient 100. The atmospheric pressure reading is performed in real time by a sensor 232 in the external processing device 106 or another atmospheric sensor that causes the data to be transferred to the external computing device 106.

  Moreover, other physiological data is transferred from the human patient, including posture, body temperature data, pressure data taken at multiple positions, which can be used to calibrate blood pressure data. Still further, step 326 may include techniques for compensating for respiration effects on blood pressure data. These are examples of types of data that can be used to provide accurate and precise blood pressure data. An external processing device 106 that is not constrained by force, computational limitations, or other constraints inherent in implantable medical devices such as the communication device 102 can more accurately calculate physiological phenomena such as blood pressure. In one embodiment, the external processing device 106 performs a calculation using a third order polynomial to describe the relationship between the stored physiological data and the actual physiological phenomenon.

  The above process is used to describe the analysis of blood pressure data, but any number of human body physiological parameters can be analyzed as well. For example, similar devices and processes are used to analyze blood oxygen levels or blood glucose levels, blood flow, and the presence of chemicals in the body.

  The result of the data calculation can be displayed for review by the external processing device 106. As described above, the external processing device 106 has a user interface 238 that includes a display screen for displaying information to a human patient, medical personnel, and others. In addition, the external processing device 106 may be a keyboard, input switch, or other suitable for inputting information to the external processing device 106, for example, to request that the device display certain information on its display. Including other devices.

  Once step 326 of calibrating physiological data is complete, step 328 of transferring the calibration data to remote database 108 via communication link 116 is performed. The data transferred to the remote database 108 can be stored along with any other information previously collected from the human patient 100. As a result, the data analysis step 330 is performed when data is received. The analysis is, for example, a trend analysis that can provide previously known or unknown chronic conditions, information about potential health concerns, or any other relevant information. Furthermore, once the information is stored in the remote database, anyone with appropriate permissions can access all relevant health information. In one embodiment, the external processing device 106 can be used to access health data from the remote database 108.

  In addition to initiating information transfer from the human patient, the external processing device 106 can interact with an implantable medical device, such as the communication device 102, to perform other functions. For example, the external processing device 106 initiates a reprogramming process within the communication device 102. Any of the software code in communication device 102 can be reprogrammed in one embodiment. This includes reprogramming sensor identification information, adding functional features, or modifying current features of other sensors placed in the human patient if necessary. By communicating via the communication link 114, the external processing device 106 can initiate and provide relevant information to complete the initialization.

  Furthermore, the external processing device 106 may also have the ability to communicate directly with the physiological sensor 104 to adjust recalibration tasks, such as adjusting calibration data or some other programming task, for example. Alternatively, the external processing device 106 may be capable of communicating with the communication device 102 and directs the communication device to communicate with the physiological sensor 104 via the communication link 114 and the physiological sensor 104. The communication device is used as a gateway for the purpose of reprogramming.

  The present invention provides a number of advantages. Calibration data in the external processing device 106 reduces the power used by the implantable medical device. Moreover, the computational power available within the external processing device 106 allows for a more precise calibration than found in implantable medical devices. Furthermore, by using a variety of different sensors placed within a human patient, the present invention can provide more meaningful data. For example, posture and body temperature affect blood pressure readings, so information from sensors to sense their physiological parameters and provide precise calibration of those readings is data available to medical professionals. Is further improved.

  Moreover, the external processing device 106 automatically initiates data collection and calibration, thereby improving the data collection process by allowing continuous periodic data collection without human intervention. Can do.

  Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, although the above embodiments refer to specific features, the scope of the invention includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the invention is intended to embrace all such alternatives, modifications and applications as fall within the scope of the claims and all equivalents thereof.

Measure physiological parameters within a human patient, transfer measurement data outside the human patient with or without human intervention, and measure outside the human patient, according to one exemplary embodiment of the invention 1 illustrates a system that uses an implantable medical device to calibrate data. 2 is a block diagram of a communication device implanted in a human patient as part of the system shown in FIG. FIG. 3 is a block diagram of a physiological sensor that is implanted in a human patient and configured to communicate with the communication device of FIG. FIG. 2 is a block diagram of an external processing device configured to communicate with one or more implantable medical devices by the human patient of FIG. 2 is a functional block diagram of a process for measuring and storing physiological data within the human patient of FIG. FIG. 7 is a functional block diagram of a process for transferring the physiological data measurements shown in FIG. 6 from a human patient for calibration and analysis.

Claims (15)

A system 110 for analyzing cardiovascular pressure data in a human body, comprising:
A first sensor 104 configured to be implanted at a first location in the human body to measure pressure data;
A communication device 102 configured to be implanted in the human body and in wireless communication with the first sensor 104 to receive the pressure data in an uncalibrated shape from the first sensor 104;
An external processing device 106 having a barometric sensor and capable of wireless communication with the communication device 102 to receive the uncalibrated pressure data, calibrates the uncalibrated pressure data, and pressure data and calibrated pressure data And an external processor 106 configured to use real-time barometric data to generate relative pressure data in real time based on   The system of claim 1, wherein the communication device is a pulse generator.   The system of claim 1, wherein the communication device is associated with a specific identification parameter to enable wireless communication of the uncalibrated pressure data from the communication device to the external processing device.   The external processing device 106 includes a plurality of unique identification parameters, and each unique identification parameter specifically identifies each of the plurality of communication devices 102, and from the plurality of communication devices 102 to the external processing device 106. The system of claim 3 enabling wireless communication of pressure data to.   The first sensor 104 is associated with a unique identifier so that the external processing unit 106 can calibrate the uncalibrated pressure data based on calibration characteristics associated with the first sensor 104. The system of claim 1, wherein the first sensor 104 can be specifically identified.   6. The external processing device 106 communicates with a network database in which calibration characteristics corresponding to the unique identifier are stored, and the external processing device 106 accesses the calibration characteristics from the network database. The system described.   The system of claim 1, wherein the external processing device further comprises the ability to provide reprogramming information to the communication device.   The system according to claim 1, wherein the external processing device is portable.   The system of claim 1, wherein the first sensor includes calibration information that adjusts pressure data collected by the first sensor and the calibration information is accessible by the external processing device.   A second sensor 104 embedded at a second location in the human body for measuring data relating to physiological parameters in the human body, wherein the second sensor 104 is in wireless communication with the communication device 102; and The system of claim 1, wherein the external data processing unit is capable of wirelessly communicating with the communication device to receive data measured by the second sensor.   The system of claim 10, wherein the physiological parameter is related to pressure at the second location.   The system according to claim 10, wherein the physiological parameter is related to a posture of a human body at the second position.   The system of claim 10, wherein the physiological parameter is related to body temperature at the second location.   The system of claim 10, wherein the physiological parameter is related to respiration.   The system of claim 10, wherein the physiological parameter is related to at least one of blood oxygen level, blood glucose level, blood flow at the second location.

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